As many sites have stated: Chasing the elusive "perfect pH" will do more harm than good. Stability is more important whether at 6.5 or 8.0. Fish cannot adapt to constantly changing parameters.
And I agree with lil, you don't need to age your water; that's what the conditioner is for. I don't think it affects the pH but someone please correct me if I'm wrong.
Also, are you using distilled water or regular bottled drinking/spring water?
And, here's a gift: If you order from Live Aquarium Plants
and put "bettafish" in the coupon section you get an additional 10% off your purchase before shipping.